How to restart a loop after capturing a wrong input?
because if i inputted a string or a character, my program captures the error but
the problem is that my program does not return from the initial spot or initial position
how can i solve that?this is my program

Code:

//This program can evaluate a 10th order polynomial single variable,
//can solve for statistical algorithms mainly mean, standard deviation
//and summation of data with a maximum of 10 data,
//can solve for ideal gas equation with the gas sample of nitrogen and
//can build a database of strings which can store of 16 strings with 128
//maximum characters, remove a string from the database, view the strings
//and search the strings inside the database